It is known to equip an indoor unit of an air conditioner with a front surface panel that opens and closes a suction port, which is provided to the front surface of a casing. This front surface panel covers the suction port when the operation of the indoor unit of the air conditioner is stopped, thereby making it possible to conceal the suction port from external view and thus improve the design qualities of the indoor unit. In addition, during operation of the indoor unit of the air conditioner, the front surface panel moves rotationally about its lower end so that it inclines frontward, thereby opening the suction port and ensuring the suction of air (refer to Japanese Published Unexamined Patent Application No. H7-98129, FIG. 1). Consequently, it is possible to simultaneously achieve good design qualities and ventilation performance.